Goldenwrench Blackline Performance BMW M Car G-Chassis Washer Fluid Cap

The Goldenwrench Blackline Performance BMW M Car G-Chassis Washer Fluid Cap is a full-replacement billet upgrade designed to address one of the more overlooked details in the M vehicle engine bay. Built as a complete swap for the factory plastic reservoir cap, this unit pairs no-spill seal technology with precision CNC construction — correcting a known OEM seepage issue while delivering a clean, finished appearance consistent with the Blackline Performance product line.

Each cap is machined from T6 aluminum and finished in a race-inspired anodized red, with all branding and logos permanently machined using 3D milling — no adhesive graphics, no decals. The finish is integral to the surface, ensuring it holds up to heat cycling, repeated cleaning, and long-term engine bay exposure. The result is a functional improvement and a visual upgrade in one component.

Installation is entirely tool-free. The billet cap replaces the factory unit directly, threading into the existing reservoir mount and seating cleanly with the integrated seal. The process takes only minutes. Each kit includes the billet washer fluid cap and an Installation Instruction Card.

Product Details

• Full replacement billet washer fluid cap — OEM unit removed entirely
• CNC-machined from T6 aluminum
• Integrated no-spill seal technology to prevent reservoir leakage
• Race-inspired anodized red finish
• 3D-milled branding — no decals or surface treatments
• Tool-free installation, direct OEM fitment
• Kit includes billet cap and Installation Instruction Card

Vehicle Applications

• G87 M2
• G80/G81 M3
• G82/G83 M4
• F90 M5
• G90 / G99 M5

Notes

• This is a full cap replacement, not a cover. Factory cap is removed during installation.
• Designed specifically for BMW G-chassis M vehicles listed above.